IUCN Status: Vulnerable
EPBC Threat Rating: Extreme
IUCN Claim: “The major threat to the Bilby is predation by introduced red foxes and feral cats’”
About 70% of bilby extirpation records (36 populations) occured 1-53 years after foxes arrived and the timing of fox establishment correlates with bilby extirpation across the country (Abbott 2001, Wallach et al 202X). Fox probability of occurrence was a negative predictor of bilby occurrence, but model uncertainty was high (Southgate et al. 2007). Bilbies reintroduced inside fenced reserves (excluding foxes, cats and dingoes) have improved survival rates (Moseby et al. 2011).
Sixteen bilby populations (~30% of records) were last recorded 0-13 years before foxes arrived (Abbott 2001, Wallach et al 202X). Bilbies were last recorded in the Murray-Darling about 20 years before fox arrival (Copley 1999). In one study foxes were not among the predators of reintroduced bilbies (Lohr et al. 2021).
The evidence for a negative association between foxes and bilby
populations is inconclusive due to high model uncertainty. A temporal
correlation between extirpation and arrival does not prove causation
since nearly a third pre-date fox arrival and confounding variables were
not tested for.
Abbott, Ian. “The bilby Macrotis lagotis (Marsupialia: Peramelidae) in south-western Australia: original range limits, subsequent decline, and presumed regional extinction.” RECORDS-WESTERN AUSTRALIAN MUSEUM 20.3 (2001): 271-306.
Fairfax, Dispersal of the introduced red fox (Vulpes vulpes) across Australia. Biol. Invasions 21, 1259-1268 (2019).
Lohr, Cheryl A., et al. “Reintroduction of Bilbies (Macrotis lagotis) to Matuwa, an Indigenous Protected Area in Western Australia.” Rangeland Ecology & Management 78 (2021): 67-78.
Southgate, Richard, et al. “Bilby distribution and fire: a test of alternative models of habitat suitability in the Tanami Desert, Australia.” Ecography 30.6 (2007): 759-776
Wallach et al. 2023 In Submission